Mark Haddon’s 2003 novel The Curious Incident of the Dog in the Night-Time depicts the strange world of Christopher Boone, a 15-year-old who describes himself as having “behavioural problems”. Commonly interpreted as a vision of what it means to live with Asperger’s syndrome, it is in fact just a portrait of a quirky young man: Christopher displays characteristics we associate with high-functioning autism, yet he is never definitively pigeonholed.

Simon Stephens seems the perfect choice to adapt it for the stage. In his play Punk Rock there is a character who feels likes he might be related to Christopher, awkwardly explaining how many stars there are in the universe.

And Stephens exults in imagining misfits — in all their sincerity and weirdness. True to the original novel, his version drips with ideas, especially about the nature of objects and the importance in our world of mathematical sequences.

The action starts with Christopher finding a dead dog. He decides to investigate how it died and ends up discovering things that throw his emotions into disarray. Fidgety, annoying and occasionally profound, he is played with a mixture of grace and feverish intensity by Luke Treadaway. He drools and squirms and groans but mostly his hallmark is a pedantic manner that borders on belligerence. It’s a performance of great physical poise and stunning conviction.

Although this is very much Treadaway’s show, he is well supported by Nicola Walker and Paul Ritter, who play his often frustrated parents. Niamh Cusack is lovely as his patient teacher Siobhan and Una Stubbs has a memorable cameo as the neighbour who divulges more than he has bargained for. The cast frequently performs as a balletic ensemble, and the movement, overseen by Scott Graham and Steven Hoggett of Frantic Assembly, is fluid.

Director Marianne Elliott confidently evokes the alien landscape of Christopher’s mind. There’s an ingenious design by Bunny Christie, which integrates effective video by Finn Ross as well as Paule Constable’s versatile lighting and poignant music by Adrian Sutton. The visual language is aptly conceived, for Haddon’s novel is full of charts and equations — Christopher doesn’t understand metaphors and favours diagrams instead.

There’s also a little dig at the recent vogue for so-called premium seats, as some members of the audience are greeted by a sign that declares “You are sitting in a prime seat”. It’s a nod to Christopher’s mathematical enthusiasms; numbers are his friends. But all the seats here are prime: humane and stylish, The Curious Incident is a success from any angle.